Apparatus and method for mounting electronic component

ABSTRACT

A solvent transfer unit is made a slide type and a plurality of nozzles at a head part which suck and hold components are moved down simultaneously to transfer the flux to electronic components. In comparison with an electronic component mounting method including a transfer operation whereby nozzles are lowered one by one by a conventional electronic component mounting apparatus equipped with a rotary type solvent transfer unit, a time for moving the nozzles up, down is shortened and a total cycle time is reduced, so that production efficiency is improved.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and a method for mountingelectronic components which carry out solvent transfer operation fortransferring solvent such as flux, solder paste, or the like toelectronic components requiring the transfer of the solvent at the timewhen the components are mounted to objects to be mounted such as boardsor components.

Electronic component mounting apparatuses these days are required tomount electronic components speedily correctly to electronic circuitboards, with improving mounting quality.

An example of a conventional electronic component mounting apparatuswill be described below with reference to FIGS. 14, 15, and 16.

A conventional electronic component mounting apparatus 10 shown in FIG.14 comprises a board transfer device 4 for carrying in and out circuitboards, a front component feed device 32 a and a rear component feeddevice 32 b each having a plurality of component feed units, a head part8 with a mechanism that can load desired suction nozzles, move up anddown, and rotate the loaded suction nozzles, a board recognition camera9, an XY robot 5 movable in X and Y directions, an electronic componentimage pickup device 2, and a solvent transfer unit 40.

The above conventional electronic component mounting apparatus 10operates in a manner as follows. The board transfer device 4 transfersthe circuit board to a mounting position. The XY robot 5 moves the boardrecognition camera 9 over the circuit board thereby checking positionswhere electronic components are to be mounted on the circuit board. TheXY robot 5 then moves the board recognition camera 9 over the frontcomponent feed device 32 a and the rear component feed part 32 b andrecognizes components 33 to be caught. Subsequently, the XY robot 5 letsthe nozzles 8 hold the electronic components 33. The electroniccomponents 33 sucked and held by the nozzles 8 are moved to the solventtransfer unit 40, where the components 33 are moved down one by one sothat the flux 50 is transferred to each of the components 33. Attitudesof the electronic components 33 held by the nozzles 8 are picked up bythe component image pickup device 2 and measured, thereby judging theresult. When the measured result of the held attitudes of the components33 is normal, the components 33 are corrected in position on the basisof the obtained image information. Thereafter the XY robot 5 is movedand the electronic components 33 are mounted onto the circuit board.

As shown in FIGS. 14, 15, and 16, in an example of the conventionalequipment, the electronic component mounting apparatus 10 has thetransfer unit 40 of a type rotating a transfer saucer 40 b toapproximately uniform a film thickness of the flux 50. The operation ofthe prior art apparatus 10 after sucking the electronic components willbe described in detail hereinbelow. The head part 6 having a pluralityof nozzles 8 for sucking and holding the electronic components 33 ismoved by the XY robot 5 to the solvent transfer unit 40 of a rotarytransfer saucer type. The head part 6, when reaching the solventtransfer unit 40 of a rotary transfer saucer type, lowers one of theplurality of sucked and held electronic components 33 to a transfer faceof the transfer unit 40, whereby the flux 50 is transferred to theelectronic component 33. After the electronic component 33 having theflux transferred thereto is moved up, the transfer saucer 40 b isrotated by a motor 40 d to approximately uniform a thickness of the flux50 with a blade 40 a. Thereafter, the nozzle 8 sucking and holding thenext electronic component 33 is moved by the XY robot 5 to a transferposition, and moved down to transfer the flux 50. The process isrepeatedly carried out for all components 33. The head part 6 is movedto a desired mounting position after the flux 50 is transferred to allof the sucked and held electronic components 33, where the electroniccomponents 33 are mounted.

In the thus-constituted conventional electronic component mountingapparatus 10 with the solvent transfer unit 40 of a rotary transfersaucer type, the flux is transferred to only one electronic component 33at each time although a plurality of the electronic components 33 aresucked and held. As such, the volatile content of the flux 50transferred to a first electronic component 33 already volatilizes atthe time when the flux is transferred to a last electronic component 33,thus causing degradation in mounting quality. A mounting time isincreased, which leads to deterioration in production efficiency.

SUMMARY OF THE INVENTION

Accordingly, the present invention is devised to solve these issues andhas for its object to provide an apparatus and a method for mountingelectronic components which can curtail a loss which would be broughtabout in a process wherein solvent is transferred to electroniccomponents one by one.

In accomplishing these and other aspects, according to a first aspect ofthe present invention, there is provided an electronic componentmounting apparatus comprising:

a component feed device for feeding a plurality of electroniccomponents;

an object support device for holding and positioning an object to whichthe electronic components are to be mounted;

a plurality of component holding members for holding the electroniccomponents from the component feed device and mounting the heldelectronic components to predetermined positions on the object;

a component image pickup device for measuring attitudes of theelectronic components held by the component holding members; and

a flux transfer unit, comprising: a solvent transfer part for forming afilm of a flux to be transferred to the components; and a film-formingblade for forming the solvent film at the solvent transfer part, fortransferring the solvent to the electronic components by bringing thecomponents held by the component holding members into touch with thesolvent film simultaneously after the solvent film is formed byrelatively and linearly sliding one of the solvent transfer part and theblade.

According to a second aspect of the present invention, there is providedan electronic component mounting apparatus according to the firstaspect, wherein the solvent transfer unit has at the solvent transferpart a flat plane portion at which the solvent film is formed and has adriving part for relatively and linearly sliding one of the solventtransfer part and the film-forming blade, thereby regulating a filmthickness of the solvent thereat through movement of the solventtransfer part or the blade thereby making the film thickness of thesolvent approximately uniform.

According to a third aspect of the present invention, there is providedan electronic component mounting apparatus according to the first orsecond aspect, wherein the component feed device has cassette slots inwhich component feed cassettes, and the solvent transfer unit is capableof being inserted into one of the cassette slots of the component feeddevice to set the solvent transfer unit at the apparatus.

According to a fourth aspect of the present invention, there is providedan electronic component mounting apparatus according to any one of thefirst to third aspects, wherein in the solvent transfer unit, one of thesolvent transfer part and the blade is slid in accordance with acomponent take-out signal indicating that the component is taken out bythe component holding member from a component feed cassette attached ata cassette slot of the component feed device.

According to a fifth aspect of the present invention, there is providedan electronic component mounting apparatus according to any one of thefirst to fourth aspects, wherein the solvent transfer unit has thefilm-forming blade and a scraping blade for scraping unnecessary flux,and after the film of the flux is formed at the solvent transfer part byrelatively and linearly sliding one of the solvent transfer part and thefilm-forming blade, the plural electronic components held by thecomponent holding members are brought into contact with the film of thesolvent to transfer the solvent to the held components, and after thesolvent left at the solvent transfer part is scraped by the scrapingblade, a new film of the solvent is formed at the solvent transfer part.

According to a sixth aspect of the present invention, there is providedan electronic component mounting apparatus according to any one of thefirst to fifth aspects, wherein the solvent transfer unit has a flatplane portion at the solvent transfer part, and when the solvent istransferred to the components, the solvent is transferred to bumpsformed on electrodes of the plural electronic components while levelingthe bumps by pressing the bumps against the flat plane portion of thesolvent transfer part.

According to a seventh aspect of the present invention, there isprovided an electronic component mounting method comprising:

relatively and linearly sliding one of a solvent transfer part and afilm-forming blade in a flux transfer unit comprising the solventtransfer part at which a film of a flux to be transferred to electroniccomponents is formed, and the film-forming blade for forming the solventfilm at the solvent transfer part, thus forming the solvent film at thesolvent transfer part; and

thereafter transferring the solvent to the electronic components bybringing the components held by component holding members into touchwith the film of the solvent simultaneously.

According to an eighth aspect of the present invention, there isprovided an electronic component mounting method according to theseventh aspect, further comprising regulating a film thickness of thesolvent at the solvent transfer part through movement of the solventtransfer part or the blade, thereby making the film thickness of thesolvent approximately uniform.

According to a ninth aspect of the present invention, there is providedan electronic component mounting method according to the seventh oreighth aspect, wherein the solvent film is formed by driving the solventtransfer part or the blade in accordance with a component take-outsignal indicating that the component is taken out by the componentholding member from a component feed device for feeding the components.

According to a tenth aspect of the present invention, there is providedan electronic component mounting method according to any one of theseventh to ninth aspects, further comprising, after the pluralelectronic components held by the component holding members are broughtinto contact with the film of the solvent to transfer the solvent to theheld components, scrapping the solvent left at the solvent transfer partby a scraping blade for scraping unnecessary flux, and then forming anew film of the solvent at the solvent transfer part.

According to an eleventh aspect of the present invention, there isprovided an electronic component mounting method according to any one ofthe seventh to tenth aspects, wherein, when the solvent is transferredto the components, the solvent is transferred to bumps formed onelectrodes of the plural electronic components while leveling the bumpsby pressing the bumps against the flat plane portion of the solventtransfer part.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and features of the present invention willbecome clear from the following description taken in conjunction withthe preferred embodiments thereof with reference to the accompanyingdrawings, in which

FIG. 1 is a perspective view of an electronic component mountingapparatus according to an embodiment of the present invention;

FIG. 2 is a diagram of a plane layout of the electronic componentmounting apparatus shown in FIG. 1 with a part of the electroniccomponent mounting apparatus omitted;

FIG. 3 is a perspective view of a solvent transfer unit of a slide typeof the electronic component mounting apparatus according to theembodiment of the present invention;

FIG. 4 is a perspective view of a driving unit of the flux transferunit;

FIG. 5 is an explanatory view of a state where flux in a recessedportion of a flux transfer stage the flux is scraped up to a flat planeportion thereof by a blade when the flux transfer stage is moved withrespect to the fixed blade by driving of the driving part of the fluxtransfer unit;

FIG. 6 is an explanatory view of a state where the flux in the recessedportion of the flux transfer stage the flux is spread on the flat planeportion thereof by the blade when the flux transfer stage is moved withrespect to the blade by driving of the driving part of the flux transferunit;

FIG. 7 is an explanatory view of a state where a film havingapproximately uniform thickness is formed on the flat plane portion bythe blade when the flux transfer stage is moved with respect to theblade by driving of the driving part of the flux transfer unit;

FIG. 8 is a plane view of the flux transfer unit;

FIG. 9 is an explanatory view of a flux transfer unit of a slide type inthe electronic component mounting apparatus according to otherembodiment of the present invention;

FIG. 10 is an explanatory view of a state where bumps are made flat byusing the flux transfer unit of a slide type in the electronic componentmounting apparatus according to other embodiment of the presentinvention;

FIG. 11 is an explanatory view of a state where bumps are made flat byusing the flux transfer unit of a slide type in the electronic componentmounting apparatus according to other embodiment of the presentinvention of FIG. 10;

FIG. 12 is an explanatory view of a state where bumps were made flat byusing the flux transfer unit of a slide type in the electronic componentmounting apparatus according to other embodiment of the presentinvention of FIG. 10;

FIG. 13 is a block diagram of the electronic component mountingapparatus according to other embodiment of the present invention of FIG.10;

FIG. 14 is a perspective view of a conventional electronic componentmounting apparatus;

FIG. 15 is a diagram of a plane layout of the conventional electroniccomponent mounting apparatus;

FIG. 16 is an explanatory view of a flux transfer unit of theconventional electronic component mounting apparatus; and

FIG. 17 is a front view of four nozzles used in the electronic componentmounting apparatus according to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the description of the present invention proceeds, it is to benoted that like parts are designated by like reference numeralsthroughout the accompanying drawings.

A solvent transfer unit of an electronic component mounting apparatusaccording to an embodiment of the present invention is to carry out asolvent transfer operation for transferring solvent such as flux or thelike to electronic components which are to be mounted onto objects to bemounted such as boards or components.

The electronic component mounting apparatus equipped with the abovesolvent transfer unit and, an electronic component mounting methodincluding the solvent transfer operation of transferring the solvent tothe electronic components with the use of the solvent transfer unit willbe described below with reference to FIGS. 1, 2, 3, and 4.

In the embodiment, as examples of the solvent transfer unit and thesolvent transfer operation, a flux transfer unit and a flux transferoperation using a flux by way of example of the solvent will be detailedhereinbelow. The solvent may be solder paste, organic solvent such asconductive paste, or the like, for example.

The description of the embodiment exemplifies the electronic componentmounting apparatus and the electronic component mounting method wherebyelectronic components corresponding to components are automaticallymounted onto circuit boards after held by nozzles as examples ofcomponent holding members.

As shown in FIG. 1, the electronic component mounting apparatus 1 in theembodiment has the flux transfer unit 100 at a portion where a componentfeed cassette is not set in a rear component feed device. The fluxtransfer unit 100 is constituted of a transfer stage 102, as one exampleof a solvent transfer unit, having recessed portions 102 b, 102 f forstoring a flux 200, and a flat plane portion 102 a for transferring theflux 200 to components 33, a film-forming and scraping blade 101 forregulating a thickness of a film 211 of the flux 200, a driving part104, such as a motor or a cylinder, for linearly sliding the transferstage 102 or the blade 101 (the stage 102 in FIGS. 1-4), and a signalreception part 105 for receiving a signal for driving of the drivingpart 104. As is clear from FIG. 2 showing a plane layout of theapparatus 1, the flux transfer unit 100 can be set at a part of the rearcomponent feed device 32 b located at the rear of the apparatus 1 bydetachably being inserted the flux transfer unit 100 to one of cassetteslots 80 of the rear component feed device 32 b.

The thus-installed flux transfer unit 100 is used in the electroniccomponent mounting apparatus 1 of the constitution as indicated in FIGS.1-4.

The electronic component mounting apparatus 1 with the flux transferunit 100 will be described now.

The component mounting apparatus 1 for electronic components includes aboard transfer device 4, serving as one example of an object supportingdevice, which carries in and out circuit boards 60 and holds andpositions the circuit boards 60 when components 33 are to be mounted;electronic component feed devices 32 a, 32 b having a plurality ofelectronic component feed units (for example, component feed cassettescapable of being inserted into the cassette slots 80 or component feedtrays) for each accommodating the electronic components 33, a head 6having the nozzles 8 which can hold the electronic components 33 fromthe feed device 32 a or 32 b and move the components 33 by an XY robot 5in X and Y directions to mounting positions on the circuit boards 60,front and rear component image pickup device 2 a, 2 b which pick up andmeasure images of held attitudes of the electronic components 33 held atthe nozzles 8 of the head 6, and a control unit 600 for controllingoperations of at least the XY robot 5, the head 6, the nozzles 8, andthe component image pickup devices 2 a, 2 b as shown in FIG. 13. Thehead 6 is equipped with the plurality of nozzles 8 for holding, e.g., bysucking the electronic components 33 and a board recognition camera 9for picking up and thereby recognizing an image of a board markindicated at the mounting position on the circuit board 60. It is notedthat for simplification, the head 6 has one nozzle 8 in FIG. 1, but, forone example, the head 6 has four nozzles 8 capable of sucking andholding four electronic components 33. As shown in FIG. 17, each of thenozzles 8 can be independently moved upward and downward by each drivingcylinder 8 d under the control of the control unit 600, so that, forexample, four nozzles 8 can be moved downward integrally, or onlynecessary nozzle(s) 8, one, two, or three nozzles 8 can be moveddownward.

As shown in FIG. 13, the control unit 600 is connected to the XY robot5, the head 6 having the plural nozzles 8, the front and rear componentimage pickup devices 2 a and 2 b, front and rear component feed device32 a and 32 b, the board transfer device 4, the board recognition camera9, and the driving part 104 of the flux transfer unit 100 to control therespective operations under the control of the control unit 600. It isnoted that there are devices such as the driving part 104 or 204 of theflux transfer unit 100, and the blade switching device 201 or 301 inthis embodiment are shown in FIG. 13, which is unnecessary in thisembodiment, but necessary in the later embodiments.

The operation of the electronic component mounting apparatus 1, mainlythe operation after recognizing the mark showing the mounting positionon the board 60 by the board recognition camera 9 will be depictedhereinbelow.

In mounting the components 33 of the component feed devices 32 a, 32 b,under the control of the control unit 600, while the head 6 is moved inX, Y directions by the XY robot 5, the board recognition camera 9 ismoved over, for example, the front component feed device 32 a, thecenters and inclinations of the to-be-sucked and held electroniccomponent 33 are recognized by the board recognition camera 9, thecenter of each of the electronic components 33 is calculated by thecontrol unit 600, and each of the electronic components 33 is held andsucked at the center by each of the nozzles 8. At this time, a componenttake-out signal indicating that the component 33 is taken out from thecomponent feed device by the nozzle 8, for example, a component feedsignal issued from the component feed cassette of the front componentfeed device 32 a or a tape releasing signal indicating that a releasetape is taken out when the component 33 is taken out from the tapedcomponent of the component feed cassette is detected at the signalreception part 105 of the flux transfer unit 100 set at the rear of theapparatus 1, and the flux transfer stage 102 is linearly slid by thedriving part 104 to approximately uniform a film thickness of the fluxfilm 211 at the flux transfer stage 102. The scraped unnecessary flux200 is collected in the recessed portion 102 b or 102 f of the fluxtransfer stage 102, so that the flux 200 is not stagnant in one of therecessed portions and is circulated between the recessed portions at alltimes.

One example of the driving part 104 is shown in FIG. 4. By driving of adriving cylinder 104 d fixed to a fixed base 104 a, a movable base 104 bconnected to a movable part 104 c of the driving cylinder 104 d islinearly and reciprocally moved with respect to the fixed base 104 awhile guided by the fixed base 104 a. The flux transfer stage 102 isfixed to the movable base 104 b to linearly and reciprocally move theflux transfer stage 102. The flux transfer stage 102 has the recessedportions 102 b, 102 f at both ends thereof and a trapezoidal sectionalportion with a flat plane portion 102 a at its top between the recessedportions 102 b, 102 f. The film-forming and scrapping blade 101 is fixedto the side of the fixed base 104 a, and a gap is defined between thelower end of the blade 101 and the flat plane portion 102 a so as toform the film 211 of the flux 200 with its approximately uniformthickness. Therefore, when the flux transfer stage 102 is linearly andreciprocally moved by driving the driving cylinder 104 d, the film 211of the flux 200 with the approximately uniform thickness is formed bythe flux transfer stage 102 and the blade 101 fixed to the side of thefixed base 104 a. For example, in FIG. 3, when the flux transfer stage102 is moved with respect to the fixed blade 101 from the upper right tothe lower left direction, from a state where the blade 101 is insertedinto the one recessed portion 102 b, a part of the flux 200 stored inthe one recessed portion 102 b is moved to the flat plane portion 102 a,a flux film 211 with its approximately uniform thickness is formed atthe flat plane portion 102 a by the blade 101, and then, the blade 101together with the unnecessary flux 200 is moved into the other recessedportion 102 f. Conversely, in FIG. 3, when the flux transfer stage 102is moved with respect to the fixed blade 101 from the lower left to theupper right direction, from a state where the blade 101 is inserted intothe other recessed portion 102 f, a part of the flux 200 stored in theother recessed portion 102 f is moved to the flat plane portion 102 a, anew flux film 211 with its approximately uniform thickness is formed atthe flat plane portion 102 a by the blade 101, and then, the blade 101together with the unnecessary flux 200 is moved into the one recessedportion 102 b. Thus, by reciprocally and linearly moving the fluxtransfer stage 102, two flux films 211 with approximately uniformthicknesses are formed at the flat plane portion 102 a by the blade 101.

Thereafter, the XY robot 5, that is, the head 6 holding the electroniccomponents 33 at the suction nozzles 8 is moved in X and Y directions tothe flux transfer unit 100 at the rear of the apparatus 1, the pluralityof the held electronic components 33 are lowered at the same time intotouch with the flux film 211 at the flux transfer stage 102 by movingdownward the plural nozzles 8, and the flux 200 is transferred to theelectronic components 33. The electronic components 33 to which the flux200 is transferred are started to be moved up simultaneously to arecognition height. The electronic components 33 after the flux transferare then moved over the rear component image pickup device 2 b, wherethe held attitude of each electronic component 33 sucked and held byeach nozzle 8 is measured and the measured result is judged whether ornot the result is normal (acceptable). If the judgment result on theheld attitudes of the electronic components 33 is normal, the head 6holding the electronic components 33 at the suction nozzles 8 is setover the desired electronic circuit board 60 by moving the XY robot 5 inX and Y directions. If the judgment result on the held attitudes of theelectronic components 33 is abnormal, the head 6 holding the abnormalelectronic component 33 at the suction nozzles 8 is moved to a componentdischarge part 3 (See FIG. 1) by moving the XY robot 5 to place theabnormal electronic component 33 on a defective component place part 31to discharge the abnormal electronic component 33 to the outside of theelectronic component mounting apparatus 1.

In the embodiment as above, the flux transfer unit 100 of a slide typeis set at the rear of the apparatus 1, the solvent can be transferred tothe electronic components by bringing the components held by thecomponent holding members into touch with the solvent filmsimultaneously after the solvent film is formed by relatively andlinearly sliding one of the solvent transfer part and the blade.Therefore, the electronic components 33 sucked and held by the pluralityof nozzles 8 can be lowered at the same time to transfer the flux 200thereto. That is, since the flux 200 is transferred at once to thesucked and held electronic components 33, a time for moving the nozzles8 up and down can be shortened in comparison with the case of the rotarytype transfer unit 40 whereby a first component is moved down, thetransfer saucer 40 b is rotated and then a second component is lowered.A Cycle time is shortened accordingly.

It is appeared that the present invention is not limited to theabove-described embodiments. Various changes and modifications can bemade.

For example, the flux transfer stage may be constituted of one recessedportion and the flat plane portion. That is, as shown in FIGS. 5-8, aflux transfer stage 202 as one example of the solvent transfer unit isconstituted by one recessed portion 202 b and a flat plane portion 202a, and there are separately provided a film-forming blade 201 b made ofrigid material such as iron and a scrapping blade 201 a made of elasticmaterial such as rubber, so that the film-forming blade 201 b and thescrapping blade 201 a may be switched by a driving part 201 c, such as adriving cylinder, of a blade switching device 201. A gap for forming aflux film is previously set between the film-forming blade 201 b and theflat plane portion 202 a, so that the flux film 211 with itsapproximately uniform thickness is formed at the flat plane portion 202a. Since no gap is set between the scrapping blade 201 a and the flatplane portion 202 a, the flux 200 on the flat plane portion 202 a can bescrapped by the scrapping blade 201 a. The flux transfer stage 202 hasgrooves 202 g at both ends of the flat plane portion 202 a which isconnected to the recessed portion 202 b.

According to the above construction, when the flux transfer stage 202 islinearly moved leftward in FIG. 5 by driving the driving cylinder 204,from a state where the scrapping blade 201 a is inserted into therecessed portion 202 b, a part of the flux 200 in the recessed portion202 b is moved to the flat plane portion 202 a by the scrapping blade201 a, and then, as shown in FIG. 6, the scrapping blade 201 a moves tothe left end while the scrapping blade 201 a scraps the almost all flux200 on the flat plane portion 202 a. Next, the scrapping blade 201 a isswitched to the film-forming blade 201 b by the driving part 201 c ofthe blade switching device 201. Next, the flux transfer stage 202 islinearly moved rightward in FIG. 5 by driving the driving cylinder 204,so that as shown in FIG. 7, the film-forming blade 201 b moves to theright end, that is, the recessed portion 202 b while a flux film 211having its approximately uniform thickness is formed at the flat planeportion 202 a by the film-forming blade 201 b. According to theconstruction, the flux film 211 having its approximately uniformthickness is formed at the flat plane portion 202 a by the film-formingblade 201 b and the unnecessary left flux 200 on the flat plane portion202 a can be surely scrapped by the scrapping blade 201 a after thecomponents 33 are bought into contact with the flux film 211. Thus, itis easy to form a flux film 211 having its approximately uniformthickness when the film 211 is formed.

Furthermore, as other construction, as shown in FIG. 9, in the aboveconstruction shown in FIGS. 5-8, one blade 301 a can be used for ascrapping blade and a film-forming blade to adjust a gap between thelower end of the blade 301 a and the flat plane portion 202 a by adriving part 301 c of a switching device 301, so that the scrappingoperation and the film forming operation can be suitably carried out.

Moreover, as shown in FIGS. 10-12, the solvent transfer unit has at thesolvent transfer part 202 a flat plane portion 202 a made of rigidmaterial, and when the flux 200 is transferred to the components 33, theflux 200 is transferred to bumps 33 e formed on electrodes 33 f of theplural electronic components 33 while leveling the bumps 33 e bypressing the bumps 33 e against the flat plane portion 202 a of thesolvent transfer part 202 with a force of, for example, 400(g/100-bumps). According to the construction, the bumps 33 e can beleveled at a constant height and becomes having an affinity for thesolvent 200 by aligning the bottom surfaces of the bumps 33 e. In thisconstruction, the bumps 33 e can be pressed against the flat planeportion 202 a of the solvent transfer part 202 in a plurality of steps,depending on the electronic component 33. The above leveling operationcan be applied to not only the plural components 33 held by the pluralnozzles 8 but one component 33 held by one nozzle 8.

When the transfer operation to the components 33 is continuously carriedout, the flux 200 can be supplied to the solvent transfer part 202 aftera predetermined number of the transfer operations is finished or after apredetermined time of period is elapsed.

In the solvent transfer operation, it is not limited to transfer thesolvent 200 to the components 33 one time. The solvent 200 can betransferred to the components 33 two times or more. For example, a firsttransfer operation of transferring the solvent 200 to the components 33may be carried out so that the components 33 have an affinity for thesolvent 200 and thereafter a second transfer operation of transferringthe solvent 200 to the components 33 may be carried out so that thesolvent 200 is sufficiently transferred to the components 33.

In the respective flux transfer stages 102, 202, the respective flatplane portions 102 a, 202 a preferably have such widths that the solventcan be transferred to, for example, four components 33.

Moreover, when for example, four nozzles 8 hold the four components 33as shown in FIG. 17 and the four components 33 need the solvent transferoperation, the four nozzles 8 simultaneously may move downward to theflux transfer stage 102, 202 to transfer the flux 200 to the fourcomponents 33. When two of the four components 33 need the solventtransfer operation, the two of four nozzles 8 may move downward to theflux transfer stage 102, 202 to transfer the flux 200 to the twocomponents 33.

In the embodiments shown in FIGS. 5-12, as shown in FIG. 13, the controlunit 600 is connected to the XY robot 5, the head 6 having the pluralnozzles 8, the front and rear component image pickup devices 2 a and 2b, front and rear component feed device 32 a and 32 b, the boardtransfer device 4, the board recognition camera 9, the driving part 104or 204 of the flux transfer unit 100, and the blade switching device 201or 301 to control the respective operations under the control of thecontrol unit 600.

As is discussed in detail above, in the electronic component mountingapparatus with the solvent transfer unit of a slide type set at the rearof the apparatus according to the present invention, and in theelectronic component mounting method including the solvent transferoperation according to the present invention, the solvent can betransferred to the electronic components by bringing the components heldby the component holding members into touch with the solvent filmsimultaneously after the solvent film is formed by relatively andlinearly sliding one of the solvent transfer part and the blade.Therefore, the plurality of nozzles are enabled to move up and downsimultaneously at the solvent transfer operation, so that a movementtime is reduced as compared with the case of moving up, down the nozzlesone by one, thereby shortening the Tact time (cycle time) and eventuallyimproving production efficiency.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications are apparent to those skilled in the art. Such changes andmodifications are to be understood as included within the scope of thepresent invention as defined by the appended claims unless they departtherefrom.

What is claimed is:
 1. An electronic component mounting apparatuscomprising: a component feed device for feeding a plurality ofelectronic components; an object support device for holding andpositioning an object to which the electronic components are to bemounted; a plurality of component holding members for holding theelectronic components from the component feed device and mounting theheld electronic components to predetermined positions on the object; acomponent image pickup device for measuring attitudes of the electroniccomponents held by the component holding members; and a solvent transferunit, comprising: a solvent transfer part for forming a film of asolvent to be transferred to the components; and a film-forming bladefor forming the solvent film at the solvent transfer part, fortransferring the solvent to the electronic components by bringing thecomponents held by the component holding members into contact with thesolvent film simultaneously after the solvent film is formed byrelatively and linearly sliding one of the solvent transfer part and theblade.
 2. An electronic component mounting apparatus according to claim1, wherein the solvent transfer unit has at the solvent transfer part aflat planar portion at which the solvent film is formed and has adriving part for relatively and linearly sliding one of the solventtransfer part and the film-forming blade, thereby regulating a filmthickness of the solvent thereat through movement of the solventtransfer part or the blade thereby making the film thickness of thesolvent approximately uniform.
 3. An electronic component mountingapparatus according to claim 1, wherein the component feed device hascassette slots in which component feed cassettes can be disposed, andthe solvent transfer unit is capable of being inserted into one of thecassette slots of the component feed device to set the solvent transferunit at the apparatus.
 4. An electronic component mounting apparatusaccording to claim 2, wherein the component feed device has cassetteslots in which component feed cassettes can be disposed, and the solventtransfer unit is capable of being inserted into one of the cassetteslots of the component feed device to set the solvent transfer unit atthe apparatus.
 5. An electronic component mounting apparatus accordingto claim 1, wherein in the solvent transfer unit, one of the solventtransfer part and the blade is slid in accordance with a componenttake-out signal indicating that the component is taken out by thecomponent holding member from a component feed cassette attached at acassette slot of the component feed device.
 6. An electronic componentmounting apparatus according to a claim 2, wherein in the solventtransfer unit, one of the solvent transfer part and the blade is slid inaccordance with a component take-out signal indicating that thecomponent is taken out by the component holding member from a componentfeed cassette attached at a cassette slot of the component feed device.7. An electronic component mounting apparatus according to claim 3,wherein in the solvent transfer unit, one of the solvent transfer partand the blade is slid in accordance with a component take-out signalindicating that the component is taken out by the component holdingmember from a component feed cassette attached at one of the cassetteslots of the component feed device.
 8. An electronic component mountingapparatus according to claim 1, wherein the solvent transfer unit hasthe film-forming blade and a scraping blade for scraping unnecessarysolvent, and after the film of the solvent is formed at the solventtransfer part by relatively and linearly sliding one of the solventtransfer part and the film-forming blade, the plural electroniccomponents held by the component holding members are brought intocontact with the film of the solvent to transfer the solvent to the heldcomponents, and after the solvent left at the solvent transfer part isscraped by the scraping blade, a new film of the solvent is formed atthe solvent transfer part.
 9. An electronic component mounting apparatusaccording to claim 2, wherein the solvent transfer unit has thefilm-forming blade and a scraping blade for scraping unnecessarysolvent, and after the film of the solvent is formed at the solventtransfer part by relatively and linearly sliding one of the solventtransfer part and the film-forming blade, the plural electroniccomponents held by the component holding members are brought intocontact with the film of the solvent to transfer the solvent to the heldcomponents, and after the solvent left at the solvent transfer part isscraped by the scraping blade, a new film of the solvent is formed atthe solvent transfer part.
 10. An electronic component mountingapparatus according to claim 3, wherein the solvent transfer unit hasthe film-forming blade and a scraping blade for scraping unnecessarysolvent, and after the film of the solvent is formed at the solventtransfer part by relatively and linearly sliding one of the solventtransfer part and the film-forming blade, the plural electroniccomponents held by the component holding members are brought intocontact with the film of the solvent to transfer the solvent to the heldcomponents, and after the solvent left at the solvent transfer part isscraped by the scraping blade, a new film of the solvent is formed atthe solvent transfer part.
 11. An electronic component mountingapparatus according to claim 5, wherein the solvent transfer unit hasthe film-forming blade and a scraping blade for scraping unnecessarysolvent, and after the film of the solvent is formed at the solventtransfer part by relatively and linearly sliding one of the solventtransfer part and the film-forming blade, the plural electroniccomponents held by the component holding members are brought intocontact with the film of the solvent to transfer the solvent to the heldcomponents, and after the solvent left at the solvent transfer part isscraped by the scraping blade, a new film of the solvent is formed atthe solvent transfer part.
 12. An electronic component mountingapparatus according to claim 1, wherein the solvent transfer unit has aflat planar portion at the solvent transfer part, and when the solventis transferred to the components, the solvent is transferred to bumpsformed on electrodes of the plural electronic components while levelingthe bumps by pressing the bumps against the flat planar portion of thesolvent transfer part.